<template>
  <div class="login_container">
    <div class="login_box">
      <!-- 头像区域 -->
      <div class="avatar_box">
        <img src="../assets/logo.png" alt="">
      </div>
      <!-- 登陆表单区域 -->
      <el-form ref="loginFormRef" :model="loginForm" :rules="loginFormRules" label-width="0px" class="login_form">
        <!-- 用户名 -->
        <el-form-item prop="username">
          <el-input v-model="loginForm.username" prefix-icon="iconfont icon-user">
          </el-input>
        </el-form-item>
        <!-- 密码 -->
        <el-form-item prop="password">
          <el-input v-model="loginForm.password" prefix-icon="iconfont icon-3702mima" type="password">
          </el-input>
        </el-form-item>

        <!-- 按钮区域 -->
        <el-form-item class="btns">
          <el-button type="primary" @click="login">登录</el-button>
          <el-button type="info" @click="resetLoginForm">重置</el-button>
        </el-form-item>
      </el-form>
    </div>
  </div>
</template>

<script>
export default {
  data () {
    return {
      // 这是登陆表单的绑定对象
      loginForm: {
        username: '',
        password: '',
      },
      // 这是表单的验证规则对象
      loginFormRules: {
        // 验证用户名是否合法
        username: [
          {
            required: true,
            message: '请输入登录名称',
            trigger: 'blur',
          },
          {
            min: 3,
            max: 10,
            message: '长度在 3 到 10 个字符',
            trigger: 'blur',
          },
        ],
        // 验证密码是否合法
        password: [
          {
            required: true,
            message: '请输入登录密码',
            trigger: 'blur',
          },
          {
            min: 6,
            max: 15,
            message: '长度在 6 到 15 个字符',
            trigger: 'blur',
          },
        ],
      },
    }
  },
  methods: {
    // 点击重置按钮，重置登录表单
    resetLoginForm () {
      if (this.loginForm.username == '' && this.loginForm.password == '')
        return this.$message.info('用户名密码为空,无需重置')
      this.$refs.loginFormRef.resetFields()
      this.$message.success('重置成功!')
    },
    login () {
      // await关键字只能放在async函数里
      // await会等待后面表达式的返回结果之后才执行下一步
      this.$refs.loginFormRef.validate(async (valid) => {
        if (!valid) return
        const { data: res } = await this.$http.post('login', this.loginForm)
        if (res.meta.status !== 200)
          return this.$message.error('账号或密码错误,登陆失败!')
        // console.log(res.meta.status)
        this.$message.success('登陆成功')
        // 1. 将登陆成功之后的token,保存到客户端的sessionStorage中
        // 1.1 项目中除了登录之外的其他API接口,必须在登录之后才能访问
        // 1.2 token只应在当前网络打开期间生效，所以将token保存在sessionStorage中
        // console.log(res)
        window.sessionStorage.setItem('token', res.data.token)
        // 2. 通过编程式导航跳转到后台主页,路由地址式 /home
        this.$router.push('/home')
      })
    },
  },
}
</script>

<style lang="scss" scoped>
.login_container {
  background-color: #2b4b6b;
  height: 100vh;
  .login_box {
    position: absolute;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    width: 450px;
    height: 300px;
    background-color: #fff;
    border-radius: 3px;
  }
  .avatar_box {
    height: 130px;
    width: 130px;
    border: 1px solid #eee;
    border-radius: 50%;
    padding: 10px;
    box-shadow: 0 0 10px #ddd;
    position: absolute;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: #fff;

    img {
      width: 100%;
      height: 100%;
      border-radius: 50%;
      background-color: #eee;
    }
  }
  .login_form {
    position: absolute;
    bottom: 0;
    width: 100%;
    padding: 0 20px;
    box-sizing: border-box;
  }
  .btns {
    display: flex;
    justify-content: right;
  }
}
</style>
